In this study, STS316L powders prepared by gas atomization are used to manufacture bulk structures with dimensions of 10 × 10 × 10 mm3 using selective laser melting (SLM). The microstructures and hardness of the fabricated 316L stainless steel has been investigated with the laser beam overlap varied from 10% to 70%. The microstructures of the fabricated STS316L samples show a decrease in the balling and satellite of powders introducing defect in the bulk samples and the porosity caused by the gap between the molten metal pools disappearing as the overlap ratio increases, whereas a low overlap ratio results in significant balling and a large amount of isolated powders due to the increased gap between the melt pools. Furthermore, the highest value in Vickers hardness is obtained for the sample fabricated by 30% overlapped laser beams. These results show that the overlap ratio of laser beams in the SLM process should be considered as an important process parameter.

• 신기훈(한국기계연구원 부설 재료연구소) | Gi Hun Shin (Powder Technology Department, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea)
• 최준필(Department of Mining and Materials Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada) | Joon Phil Choi (Mcgill University)
• 김경태(한국기계연구원 부설 재료연구소) | Kyung Tae Kim (Powder Technology Department, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea) Corresponding author
• 김병기(울산대학교 첨단소재공학부) | Byoung Kee Kim (Department of Materials Science and Engineering, University of Ulsan, Ulsan 44610, Republic of Korea)
• 유지훈(한국기계연구원 부설 재료연구소) | Ji Hun Yu (Powder Technology Department, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea) Corresponding author